Diabetic mastopathy: a clinicopathologic study in palpable and nonpalpable breast lesions.

Diabetic mastopathy is a distinct clinicopathologic entity with specific histopathologic characteristics which include keloidal fibrosis, epithelioid fibroblasts, widespread periductal/lobular lymphocytic infiltration, and widespread perivascular lymphocytic infiltration. We report the clinical and histopathologic breast tissue findings of 20 patients with diabetes mellitus as compared to 20 age-matched controls. The control patients also were matched for diseases other than diabetes mellitus. All patients with diabetes mellitus showed at least one of the histologic findings of diabetic mastopathy: 13 patients (65%) showed all four histopathologic characteristics; one patient showed three; one patient showed two; and five patients showed one feature. The 20 control patients did not demonstrate any of the four histopathologic features of diabetic mastopathy. We confirm previously reported findings of diabetic mastopathy presenting as palpable breast masses in insulin-dependent diabetics. However, we also suggest that diabetic mastopathy should be expanded to include the histopathologic findings characteristic in diabetic patients with nonpalpable mammographic abnormalities and breast tissue distant to the site of involvement by carcinoma.